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What is an FMS?• A flexible manufacturing system (FMS) is a manufacturing

system in which there is some amount of flexibility that allows the system to react in the case of changes, whether predicted or unpredicted.

• Two categories of flexibility– Machine flexibility, covers the system's ability to be changed to

produce new product types, and ability to change the order of operations executed on a part.

– Routing flexibility, which consists of the ability to use multiple machines to perform the same operation on a part, as well as the system's ability to absorb large-scale changes, such as in volume, capacity, or capability.

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FMS and FMC• Early FMSs were large and very complex, consisting of dozens of CNCs

and sophisticated material handling systems. They were very automated, very expensive and controlled by incredibly complex software. There were only a limited number of industries that could afford investing in a traditional FMS as described above.

• Currently, the trend in FMS is toward small versions of the traditional FMS, called flexible manufacturing cells (FMC). – Today two or more CNC machines are considered a flexible cell and two

more more cells are considered a flexible manufacturing system. – Thus, a Flexible Manufacturing System (FMS) consists of several machine

tools along with part and tool handling devices such as robots, arranged so that it can handle any family of parts for which it has been designed and developed.

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• A flexible manufacturing cell (FMC) consists of two or more CNC machines, a cell computer and a robot.

• The cell computer (typically a programmable logic controller) is interfaced with the microprocessors of the robot and the CNCs.

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FMS Components

• Most FMS systems comprise of three main systems– Work machines (typically automated CNC

machines) that perform a series of operations;– An integrated material transport system and a

computer that controls the flow of materials, tools, and information (e.g. machining data and machine malfunctions) throughout the system;

– Auxiliary work stations for loading and unloading, cleaning, inspection, etc.

FMS Components

• Numerical Control (NC) machine tools• Automated material handling system (AMHS)– Automated guided vehicles (AGV)– Conveyors– Automated storage and retrieval systems (AS/RS)

• Industrial Robots• Control Software

Illustration example of a FMS

Flexible Manufacturing System

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FMS Goals

• Reduction in manufacturing cost by lowering direct labor cost and minimizing scrap, re-work, and material wastage.

• Less skilled labor required.• Reduction in work-in-process inventory by eliminating the

need for batch processing.• Reduction in production lead time permitting

manufacturers to respond more quickly to the variability of market demand.

• Better process control resulting in consistent quality.

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Advantages of FMS• Faster, lower- cost changes from one part to another which

will improve capital utilization • Lower direct labor cost, due to the reduction in number of

workers • Reduced inventory, due to the planning and programming

precision • Consistent and better quality, due to the automated

control • Lower cost/unit of output, due to the greater productivity

using the same number of workers • Savings from the indirect labor, from reduced errors,

rework, repairs and rejects

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Disadvantages of FMS

• Limited ability to adapt to changes in product or product mix (e.g., machines are of limited capacity and the tooling necessary for products, even of the same family, is not always feasible in a given FMS)

• Substantial pre-planning activity • Expensive, costing millions of dollars • Technological problems of exact component positioning

and precise timing necessary to process a component • Sophisticated manufacturing systems

An outline for Mechanical Engineering CAD/CAM laboratory Integrated System

An example of a simple and modern manufacturing

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Universal Machining Center

AGV transport system 1

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FMS Example One Design + One Assembly Process = Multiple Models

When different models are designed to be assembled in the same sequence they can be built in the same plant.This maximizes efficiency and allows the company to respond quickly to changing customer

FMS ExampleThrough the use of reprogrammable tooling in the body shop, standardized equipment in the paint shop and common build sequence in final assembly, Ford can build multiple models on one or more platforms in one plant.

In the body shop, where the sheet metal comes together to form the vehicle’s body, flexibility means more than 80 percent of the tooling is not specific to one model. It can be reprogrammed to weld a car or a truck or a crossover of similar size.

Body Shop

In the paint shop, flexibility means robotic applicators are programmed to cover various body styles – as they move through the paint booth – with equal precision. This results in minimizing waste and environmental impact while maximizing quality.

Paint Shop

In the final assembly area, flexibility means the build sequence is the same among multiple models on one or more platforms allowing for efficient utilization of people and equipment.

Final Assembly

FMS Example

Virtual VerificationVirtual manufacturing technology allows Ford to quickly add various models into an existing facility – or to reconfigure an existing facility to produce a new model. In the virtual world, manufacturing engineers and plant operators evaluate tooling and product interfaces before costly installations are made on the plant floor. This method of collaboration improves launch quality and enables speed of execution.